Circuit interrupter



CIRCUIT I NTERRUPTER Filed July 5, 1922 Yigl.

WITNESSES: INVENTOR ATTORNEY Patented May 351, 3%27 wires orro n. ascnnonz, or wrrlnrnssnne,

Fries.

PENNSYLVANIA, ASSIGNOR T0 WESTING- VANIAQ Application filed July My invention relates to circuit interrupters and particularly to an improved means for efiecting an opening movement between two relatively movable contact members and extinguishing an are that may be formed thereacross.

My invention is particularly applicable to interrupters for alternating currents, aithough it may be employed in connection with direct-current circuits, and it has for one of its objects the provision of means whereby a final separation between contact members may be made when the current in the circuit reaches a' predetermined value, or in the case of alternating currents, when the crest of a current wave is reached.

It is an object of my invention to provide arcing tips of such construction that the magnetic flux causes separation of the arcing tips when the current attains a prede= termined value, and particularly, when the voltage is at or near its peak because the duration of the are between the time of its inception and the time that it is extinguished at, or near, zero may be little more than a quarter cycle.

Another object is to provide arcing tips of such-"construction that the flux incident to the flow of current through the contacts tends to move the arc outwardly from the main contacts'and from the extremities of the arcing tips and cause its elongation to facilitate interruption thereof.

Another" object of my invention is to so arran e the relatively movable switch members t at magnetic forces are set up therein to act as a blowout field for arcs.

Still another object of my invention is to simplify and improve generally the construction and operation of circuit interrupters.

In connection with the interruption of alternating current circuits, tests have shown that, if an arc is .formed when the current is approximately at its maximum value, arc rupture is facilitated. The short periodmf arc duration secured is attributed to the rapid arc stream and terminal movement available at the beginning of rupturing, through utilization of magnetic forces.

As shown in the accompanying drawings,

' inrnnnnrrnn.

Serial No. 572,967.

Figure l. is a view, in side elevation, of a portion of a circuit breaker embodying my invention, and" fig. 2 is a view of a portion of the device Fig. l, in end elevation.

V1 hile have illustrated my invention as applied to circuitbreaker designed for use in connection with a quenching fluid tank (not shown), it is also applicable to circuit breakers of the carbon or air-break type.

The breaker comprises a lifting rod 3 that carries, at its lower end, a bridging member l that may be moved into and out of engagement with a pair of stationary contact members or brushes 5 that are arranged upon conductors 6.. Stationary arcing tips 7 are also secured tothe conductors 6, and movable arcing tips 8 are pivotally mounted upon the bridging member 4 and are biased towards advanced position by sprlngs 9.

The arcing tips 7 and 8 are accordingly so arranged that they extend in horizontal planes laterally away from the main contacts and are provided with ofiset portions for constituting a space 9 between the arcmg t1ps.

When the bridging member 4 is moved out of engagement with the contact brushes 5, contact of the arcing tips 7 and 8 is maintamed by the spring 9 pressing against the tips 8. With current flowing through the arcing tips 7 and 8, the field of flux about the parallel spaced portions of the arcing tip is additive in the space between the tip, dueto current flowing in opposite directions through the parallel portions of the tips; A repulsive force istherefore imposed between the arcing tips that causes them to separate, and as this force is proportional to the current, the spring 9 may be adjusted I to regulate the force necessary to cause separation of the tip. This adjustment is preferably so made that the tips separate and start the are when the voltage is almost at its peak, thereby reducing the duration of the are which is extinguished when the volt age is near zero. I

In order to obtain maximum flux density and hence maximum repellantforce in the vicinity of the space 9 the reluctance of the the arc, the tendency of the flux is to drive the arc outwardly toward the extremities of the arcing tips and to finally so elongate it that its resistances causes it to be interrupted when the voltage is near the zero portion of its cycle.

The displacement of the arc terminals and the arc stream, in a relatively short period,

- from the original arcing zones prevents accumulation of gaseous and conducting material in such zones and thereby precludes re-establishment of the are when the line voltage has passed through zero.

Various modifications and changes may be made herein, without departing from the spirit and scope of the invention as define by the accompanying claims.

I claim as my invention:

1. The combination, in an electricswitch, of a pair of relatively movable contact members, means for yieldingly holding the contact members in engagement, and means constituting portions of the contact members for controlling the magnetic forces set up by the flow of current through the said members to exert a force in opposition to the said yielding means.

2. The combination in an electric switch provided with a pair of relatively movable contact members, of metallic means for concentrating the magnetic forces set up by the passage of current through the switch for exerting an opening force on said contact members. v

3. The combination in an electric switch provided with a pair of relatively movable contact members, of means integral there-' with for concentrating the magnetic forces set up b the passage of current through the switch for exerting an opening force on the contact members and for exerting a blow-out forceon arcs formed across the contact members when separated.

4. The combination in an electric switch provided with a pair of relatively movable contact members, of metallic blocks for utilizing magnetic forces set up by the passage of current through the switch for exerting an opening force on saidcontact members, and means for yieldingly holding the contact members closed against said force but permitting them to open when such force exceeds a predetermined ,value. v

5. The combination with a circuit interrupter provided with a pair of relatively movable contact members, one of which is yieldingly held in advanced position, of magnetic means for efiecting a separation of the contact members upon the occurrence of predetermined conditions in the circuit.

6. The combination with a circuit interrupter provided with a pair of relatively movable contact members, one of which'is yieldingly held in advanced position, of magnetizable members carried by the said contact members and so arranged that repellant magnetic forces are set up between the contact members.

7. The combination with a circuit interrupter provided with a pair of relatively movable contact members, one of which is yieldingly held in advanced position, of magnetizable members carried by the said contact members and so arranged that repellant magnetic forces are set up between the contact members to effect a separation there of and to exert a blow-out field for arcs that may become established thereacross.

8. The combination with a pair of rela-' tively movable overlapping substantiallyparallel conductors so disposed as to form a loop-like path for a flow of current, of means co-operating with the said conductors to augment the magnetic fields developed by the said current.

9.. The combination with a pair of relatively movable overlapping substantially parallel conductors so disposed as to form a.

loop-like path for a flow of current, of magnetic means for reducing the reluctance of the flux paths that are established around the conductors when current flows therethrough. I

10. The combination with a pair of relatively movable main contact members, of a pair of relatively movable auxiliary contact members comprising parallel-extending spaced portions terminating in engaging faces whereby repellent magnetic forces are concentrated between the auxiliary contact members. a

, 11. The combination with a pair of rela-' spaced portions terminating in engaging faces provided with arcing tips whereb repellant magnetic forces are concentrate between the auxiliary contact members for repelling the auxiliary contact members and for serving as a magnetic blow-out field for the arcing ti s.

I a 12. In a circuit breaker, a pair of contact members and a curved arcing-tip member for, and extending at an angle to each contact member, the radius of curvature of one arcing-tip member varying outwardly from the point of engagement with the contact member, and the other arcing-tip member having an outer portion disposed at substantially a right angle to the plane of the face of its associated contact member.

13. In a circuit breaker, a pair of contact members and a curved arcing-tip member for, and extending at an angle to each contact member, the radius of curvature of one arcing-tip member varying outwardly from the point of engagement'with the contact member and theother arcing-tip member 10 having an outer portion disposed at substanber, whereby a divergent relation exists between the arcing tips.

In testimony whereof, I have hereunto subscribed my name this 28th day of June,

@TTU H. ESCHHOLZ. 

